The present disclosure relates to subject matter contained in Japanese Patent Application No. 4-33009 (filed on Feb. 20, 1992), which is expressly incorporated herein by reference in its entirety.
1. Field of the Invention
The present invention relates to a thermographic endoscope which is used to detect a temperature distribution in a part under inspection in a body cavity.
2. Description of the Prior Art
Medical endoscopes are widely used for various purposes, for example, detection of cancer. It is, however, extremely difficult to detect an early cancer, a malignant tumor under the mucous membrane, etc. by the naked eye.
However, since the temperature of abnormal cells such as cancer cells is a little higher than that of normal cells, an early cancer, a malignant tumor, etc. can be discovered by detecting a temperature distribution in the mucous membrane of the body cavity by using an endoscope. Attempts have already been made to effect such a detection by using a thermographic endoscope.
A typical thermographic endoscope, which is used for the above-described purposes, is arranged such that an infrared image that is formed in the distal end of the insert part of the endoscope is transmitted through, for example, an infrared image transmitting fiber bundle to the outside of the insert part of the endoscope, where the infrared image, that is, a temperature distribution, is visually displayed in the form of variations in color by using, for example, a thermovision.
However, the minimum temperature difference (resolving power) that can be detected with a thermovision through an infrared image transmitting fiber bundle is generally of the order of 1.degree. C. Therefore, if the temperature difference between abnormal and normal cells is smaller than 1.degree. C., the existence of abnormal cells cannot be detected.